(i) Technical Field
The present invention relates to a material supplying container which is used in an image forming apparatus such as a copying machine, a printer, a facsimile, a complex machine of these factors, etc. which forms an image on a recording medium such as recording paper, employing electro photographic system.
(ii) Related Art
The image forming apparatus employing the electro photographic system such as a copying machine and a printer is so constructed that an electrostatic latent image formed on a photoconductive drum, for example, is developed with a developer (toner) by a developing device to form a toner image, and this toner image is transferred to a recording medium such as recording paper to be fixed thereon.
Developing system in the developing device to be employed in the image forming apparatus of the above described type includes one-component developing system in which magnetic toner is used, and two-component developing system in which two-component developer containing toner and magnetic carrier mixed is used. Recently, particularly in a color image forming apparatus, the two-component developing system in which color toner not containing magnetic particles is used is a mainstream.
In whichever developing device of the one-component developing system or the two-component developing system, it is necessary to provide a structure for replenishing the toner which will be consumed along with formation of images.
Generally, replenishment of the toner is performed by using a developer container (a toner cartridge) which is detachably mounted on the developing device.
The toner cartridge is provided with an opening for supplying the toner to the developing device. The opening is closed by a seal member to contain the toner in the toner cartridge.
The seal member which closes the opening is so constructed that the opening can be opened by operation from the exterior, after the toner cartridge has been mounted on the developing device. In this manner, the toner can be prevented from scattering, when it is supplied to the developing device.
As the seal member for this purpose, use of a seal tape is known. In a structure where the seal tape is used, the seal tape is bonded to the toner cartridge so as to cover the opening, and folded back at one end of the opening in a longitudinal direction to be returned to the other end side, so that a distal end of the seal tape is projected outward. Accordingly, by pulling the tip end which is projected outward, the seal tape will be removed from a depth in the toner cartridge, whereby the opening can be opened.
As the seal tape, a so-called heat seal is used in many cases. The heat seal is made of a resin tape as a substrate having a fusible layer which will be fused by heat formed on its one face, and when the fusible layer is heated and pressurized with a hot plate or the like, the fusible layer will be fused and bonded to an objective position (the opening).
Moreover, as another system for replenishing the toner, there has been known an image forming apparatus which is so constructed that an image forming unit (a so-called process cartridge) in which a developing device having a toner storage container and a photoconductive drum are integrally incorporated can be exchanged as a whole. The image forming unit is detachably mounted on a main body of the image forming apparatus. Generally, in the image forming unit, components of other mechanisms related to electro photographic process to be disposed around the photoconductive drum are also integrally incorporated.
Even in the image forming unit as described above, a toner containing room which contains the toner is shut from the developing device by the seal member so that the toner can be prevented from leaking outside through the developing device during transportation or so. As the seal member, the structure using the above described seal tape is employed in many cases, so that opening operation can be done from outside of the image forming unit. In order to exchange the image forming unit, a new image forming unit with its seal member removed will be mounted on the main body of the image forming apparatus. Because the seal member isolates the toner containing room from the developing device in the image forming unit, the toner will not be scattered immediately, when the seal member is removed to do the mounting work.